Drum dryer feed distribution apparatus



p 8, 1959 A. M. FISCHER 2,903,054

DRUM DRYER FEED DISTRIBUTION APPARATUS Fild March 10, 1955 2Sheets-Sheet 1 FEED . ATTORNEY p 8, 1959 A. M. FISCHER 2,903,054

DRUM DRYER FEED DISTRIBUTION APPARATUS Filed March 10, 1955 2Sheets-Sheet 2 INVENTOR 1445567/7/7506466 BY m fwu ATTORNEY ilnitedStates Patent DRUM DRYER FEED DISTRIBUTION APPARATUS Albert M. Fischer,Dowa'giac, Mi'ch., assignor to Davenport Machine and Foundry Company,Davenport, Iowa, a corporation of Iowa Application March 10, 1955,Serial No. 493,439

'3 Claims. (Cl. 159-43) The present invention relates to a dryer feeddistribution apparatus and more particularly to an apparatus whereby theflow of feed material to drying surfaces is evenly distributed over thelength of the dryer drums and where the flow from such distributionapparatus is quickly and positively controlled so that no substantialresidual dripping can occur which would result in damage to the dryersurfaces or associated apparatus.

It is customary practice in the art of yeast drying, for example, toprovide perforated pipes through which a yeast slurry is directlydistributed between the surfaces of rotating drum dryers of the doubledrum type or some types of single drum dryers. The perforated pipe issuspended over the dryer. In the case of double drum dryers the yeastmaterial is puddled between the drums and thus spread onto the drumdryer surfaces. Pendulum type feeders are also well known whichoscillate while making distribution of the feed. Such feed apparatushave a common disadvantage inv that when the dryers are shut down thefeed material continues to drip and dry on the hot drums, and the cakedmaterial then forces fracture of the shear pins or may even damage thedryer or associated apparatus when the dryer is started again. Thisdifficulty is most serious where double drum dryers are used andmisalignment frequently occurs where the cake forces the separation ofthe dryer drums. This is true in even brief shutdowns since the heat inthe drums quickly solidifies the dripping yeast. Service to prepare suchcaked drums for return to operation is costly and time consuming.Frequently misalignment caused by the drip formed cake requires theskilled services of mill Wrights to restore the machinery to operation.Finally, there is little or no preheat of the fed yeast slurry in thepresently known apparatus.

It is therefore an object of the present invention to provide asubstantially dripless feed distributor.

It is another object to provide a feed distributor having positiveshut-off so that when a drying machine is shut down no dripping of thefeed material occurs.

It is another object to provide an apparatus for evenly distributing aflow of feed to the drum faces of dryers.

Another object of the invention is to obtain'better coating of the drumswith the feed material to be dried. This is accomplished by extendingthe bafiles of the feed distributor far enough to the sides so as toassure that the descending films of the feed material contact the drumsat points located approximately 45 degrees or less oif drum center.

Still another object of the present invention is to provide a feedslurry distribution apparatus wherein the apparatus serves as anefficient heat exchange surface and wherein the flow of slurry covers abroad surface thus preheating the feed and achieving substantialpreevaporation in the feed system.

Other objects including simplicity of structure, adaptability to a widerange of feed distributor installations,

relatively service-free performance, and other objects will 2,903,054 IPatented Sept. 8, 1959 2 become increasingly obvious to those as thedescription proceeds.

Inthe drawing: Figure 1 is a plan view showing the positioning of thefeed distributor apparatus over a double drum dryer. Figure 2 is an endelevation of the feed distribution apparatus positioned above andbetween the drums of a double drum dryer and-indicates, the manner ofits suspension from the hood or dryer frame members.

Figure 3 is a side elevation view of a simple form of feed distributingapparatus in accord with the present invention.

Figure 4 is an end elevation of. the structure shown in Figure 3.

Figure 5 is a side elevation view of a modified feed distributingapparatus in accord with the present invention and illustrating the useof a perforated feed tube suspended over the trough.

Figure 6' is an end elevation of the structure'shown in Figure 5.

Figure 7 is an end view of a modified form of the inventive structureshowing. a single inclined planar baifie. Figure 8 is a schematic flowdiagram showing the simplest solenoid form of valve coordinating meansas between supply line and dumping to reservoir from the drainline.

skilledintheart General description In general, a lippedlevel trough isprovided. A feed inlet tube permits the feed material in slurry form toHow into the trough portion with relatively even distribution. As thelevel of feed rises in the trough, the feed material flows uniformlyover a lip and over an inclined bafile forming a spillway to flow thefeed uniformly thereover in a thin film of substantially equal depth.The feed material flows oif the bafile and onto the dryer surface 'in'auniform stream. In double drum dryer installations a double lip, one oneach side of the trough, distributes materials to both dryer drumssimultaneously. The surface area provided by the baflle and thefilm-like flow over the baffle assists in pre-heating the feed materialprior to its contact with the dryer drum surfaces and thus makes use ofthe rising steam and radiating heat from the dryers. The apparatus flowsfeed onto the dryer drums only inresponse to arising level of feedmaterial in the trough. Valving is provided in the feed line to thedistribution apparatus and in the drain line therefrom. If a dryer shutdown is necessary and the valve to the distribution apparatus is closedno dripping can occur and the flow to the drum surfaces stopssubstantially with the closing of the valve. The simultaneous opening ofa drain valve provided below the level of full trough prevents apossibility of drip by exhausting the feed slurry from the'trough. Aswill be seen, automatic linkage can be applied to render the valve shutoff automatic in coordination with any interruption of the dryermovement. Simultaneously, the opening of the drain line avoids anypossibility of-overflow. The baffles extend inclinedly toward the drumsurfaces and terminate a short measured distance therefrom.

It will be seen that the thermal eificiency o'f dryers has beensubstantially enhanced by the distributing apparatus described andprolonged trouble-free operation characterizes the structure. Damage todryers employing the drip-free feed distributing system has thus beenreduced to new minimums. The feed trough assures better coating of thedryer drum with the feed material. This is due to the fact that thedescending feed film contacts the drums at a position about 45 degreesor less oif drum center making possible more efiicient use of the dryerdrum surface.

Specific description Referring more particularly to the drawings, atFigure 1 is the installation of a feed distributing apparatus 11 over a'double drum dryer 12. The double drum dryer 12 is shown in light linesand is illustrative of one installation. In Figures 1 and 2 the feeddistributing appara tus 11 is presented in plan and end elevationrespectively to illustrate the position of the tube 13, elongate trough14, lips 15 and 15a and drain connection 16. The pipe connection inlet17 is shown to indicate the connection to a feed supply line 18 as shownschematically in Figure 1. Likewise the drain 16 is shown schematicallywith valves 19 and 19a, where valve 19 is the feed inlet valve.

The trough 14 longitudinally cradles the tube 13. The tube 13 deliversfeed material to the trough 14 at one end. The other end of the trough14 is substantially closed except for a drain pipe 20 having a drainopening connecting with a valved drain line 16 (Figure 1). The trough 14is substantially U-shaped and is provided with inclined planar sidebaffles 22 and 22a. The baffles 22 and 22a are integrally connected tothe trough 14 and form at the lips 15 and 15a the full level line of thetrough 14. End barriers 23 and 24 close the trough 14 against the periphery of the tube 13 at one end and the drain pipe 20 at the other end.

In Figure 5 a modified version of the dripless distribution system isillustrated where a delivery tube 25 supports suitable brackets 26extending downward to support the trough 14. Where a vapor hood 27 isemployed, as in Figure 2, attachment of the delivery apparatus 11 issimply made by the attachment of adjustable screw bolts 28 .to the hood27. The adjustable screw bolts 28 provide simple leveling means for theapparatus 11. The feed tube is perforated uniformly as indicated at 29to deliver feed material in streams to the trough 14. Where yeastslurries constitute the feed, orifices 29 of approximately 4 inchdiameter have proved most satisfactory. As previously described, thelips 15 and 15a of the trough 14 determine the liquid level of thetrough 14 and the feed material spills uniformly over the baffies 22 and22a and onto the drum surfaces 30 and 30a. In this modification thetrough 14 is provided with a drain nipple '31 connected to a suitabledrain line 16 (Figures 1 and 5). The advantage of this modification isto evenly distribute the feed material over the entire length of thetrough 14 and thus assure uniform overflow over the lips 15 and 15a. Itcan be seen that the feed material will be preheated while in the trough14 and while flowing over baffles 22 and 2211 due to the large amountsof steam emanating from the boiling feed material between the 'drums 30and 3001, as well as the heat radiation from the drums 30 and 30a.Further preheating takes place as the film of material flows from thebaffles 22 and 22a onto the drums 30 and 30a as illustrated in Fig. 2.Such diffusing has been found to contribute to a desirablepre-evaporation or pre-drying of the feed slurry. It will be observedthat the trough 14 and the downwardly inclined planar baflles 22 and 22aare similar in both modifications. I

In Figure 7 it will be seen that a trough 14 embodying the principlesdemonstrated in the previously described structure is provided but thatonly one baffie 22 and one lip- 15 is provided. This modification isobviously for use where only a single surface is served by thedistributing apparatus 11a.

In all forms of the distribution apparatus the baffles 22 and/ or 22aextend outwardly and downwardly from above the dryers 12 so as todistribute material to the drums 30 and 30a within a quadrant about 45degrees or less off drum center, as shown in Figure 2.

The material comprising the troughs 14 and batfies 22 and 22a ispreferably non-corrosive sheet metal of sulficient gauge to providesupport strength while providing a maximum thermal exchange function asa thermal 4 exchange barrier interposed between the rising heat sourcefrom the dryer drums 30 and 30a and the boiling feed material.

The feed line 32 is valved as at 19 and the drain line 16 is providedwith a drain valve 19a. While these valves 19 and 19a are manual insmaller installations it will be understood that coordinated automaticcontrols are available such as solenoids, hydraulic or pneumaticactuation so that when the feed valve 19 is open the drain valve 19a isclosed and when the feed valve 19 is closed the drain valve 19a is open.Similarly the actuation of these valves 19 and 19a can be coordinatedwith the actuating means for the dryers 12 for example, so as to causedesired operation depending upon whether or not the dryer machinery isfunctioning. In Figure 8 there is illustrated a simple form ofcoordinating means wherein the valves 19 and 19a are actuated bysolenoid means. The combination valves and coordinating means C isavailable commercially from the Hannafin Corporation of Des Plaines,Illinois, and other valve manufacturers. While solenoid coordinatingmeans are convenient, it will be appreciated that other manual,hydraulic, and pneumatic controls well known in the art are alsouseable. In such a manner stoppages are instantaneously sensed by thedistribution apparatus 11 and no damage from dripping feed to hot drumsurfaces can occur. Since such automatic actuation is non-inventive perse and well known in electrical, hydraulic, and pneumatic control art nospecific description is believed necessary of equivalent control meansfor coordinating the valve actuation.

Operation In operation, for example, with double drum. dryers 12 thedistribution device 11 is suspended absolutely level above the rotatingdrum surfaces 30 and 30a and the longitudinal axis of the trough 14 islocated directly above the line of approximate contact between the drums30 and 30a. The planar downwardly inclined baffles 22 and 22a extendabove the drums 30 and 36a as best illustrated in Figure 2. The trough14 is filled by opening the valve 19 and closing the drain valve 19a. Asthe trough 14 fills beyond the level of the lips 15 and 15a the feedmaterial spills uniformly down the baflles 22 and 22a and drops onto thedrum surfaces 30 and 30a. The baffles 22 and 22a thus form a film flowspillway uniformly distributing the feed material slurry to the dryersurfaces. The location of the distribution apparatus 11 and itsconstruction permits the feed material to be preheated by the otherwiselost rising steam and radiated heat from the heated dryers. The surfaceexchange area represented by the trough 14 and baffles 22 and 22a andeven the free drop of film flow from the baffies 22 and 22a contributesto the overall thermal efiiciency of any dryer unit.

In the instance of the modification shown in Figure 5, the free dropfrom the suspended feed tube 13 is an added element contributing topreheat and consequent drying 'or evaporation.

The use of the instant apparatus with single drum dryers follows theoperational description above except that flow of feed is over onebaffle 22 as illustrated in Figure 7.

In operation higher dryer production has resulted from installationsutilizing the apparatus described and machinery damaging drip has beensubstantially eliminated. In use with either manual or automatic inletand drain valves the structure has obtained an excellent reception inthe drying art and in particular the yeast drying field.

While the description has related the apparatus to the yeast dryingfield it will be understood that the feed distributing apparatus is ofbroader scope wherever the uniform feeding of a material slurry isdesired to evaporator or dryer surfaces, and whether those surfaces beplanar or cylindrical, as in the instance of drum dryers.

Having thus described my invention it will be understood that certainmodifications within the skill of the art are intended to be included aslimited only by the scope of the hereinafter appended claims.

I claim:

1. In a feed distributing apparatus for supplying drum dryers with acontinuous slurry of preheated material, the combination including: aleveled trough having side walls and positioned over a rotary drum dryerto receive radiant heat therefrom; planar bafiies extending downwardlyand outwardly from said side walls and forming a spillway for slurrymaterial; lips at the juncture of said balfies and said side wallsdefining a liquid level over which slurry material flows film-wiseacross said baffles; a feed inlet delivering said material to saidtrough; a drain line for emptying said trough; a valve in said inlet anda valve in said drainline; and valve coordinating means for opening oneof said valves and simultaneously closing the other of said valves.

2. In a feed distributing apparatus for supplying drum dryers with acontinuous slurry of preheated material, the combination including: aleveled thin-walled trough having side walls and positionable over arotary drum dryer to receive radiant heat therefrom; planar bafilesextending downwardly and outwardly from said side walls and forming aspillway for slurry material; lips at the juncture of said baffles andsaid side walls defining a liquid level over which slurry material flowsfilm-wise across said baflies; a feed inlet delivering said material tosaid trough; a drain line for emptying said trough; a valve in saidinlet and a valve in said drainline; and valve 6 coordinating means foropening one of said valves and simultaneously closing the other of saidvalves.

3. In a feed distributing apparatus for supplying drum dryers with acontinuous slurry of preheated material, the combination including: aleveled thin walled trough having side walls and positionable over andbetween a pair of parallel axised rotary drum dryers to receive radiantheat therefrom; planar bafiles extending downwardly and outwardly fromsaid side walls and forming a spillway for slurry material; lips at thejuncture of said baflies and said side walls defining a liquid levelover which slurry material fiows film-wise for delivery to each of saidrotary drum dryers; a feed inlet delivering said material to saidtrough; a drain line for emptying said trough; a valve in said inlet anda valve in said drainline; and valve coordinating means for opening oneof said valves and simultaneously closing the other of said valves.

References Cited in the file of this patent UNITED STATES PATENTS849,003 Macklind Apr. 2, 1907 1,604,036 Golding et a1. Oct. 19, 19262,330,922 Riegler Oct. 5, 1943 2,357,868 Beardslee Sept. 12, 19442,392,382 Harcourt Ian. 8, 1946 FOREIGN PATENTS 330,129 Germany Dec. 8,1920 123,534 Sweden Dec. 7, 1948

